Farmers say kangaroos are eating them out of grass in areas where they are struggling with drought conditions.

Supplied: Tracey Walker

Kangaroos are an iconic symbol of Australia and seeing one is on the top of every tourist's must-see list, but there are too many of them according to farmers and they want to triple the number they can shoot.

After being decimated during the long drought years from the late 1990s to 2008, aerial surveys by state government agencies indicatethat kangaroo numbers are up again at record levels.

There are about 50 million kangaroos now, about double the human population, with 22 million in Queensland and a record 17 million in New South Wales, according to the Office of Environment and Heritage in that state.

He said roos were eating pastures that farmers desperately needed for livestock.

"We've got a proliferation of kangaroos, they're in plague proportions and we need to do something about it," he said.

There is some research from the Australian National University and Deakin University that supports the claim that they are having an impact on agriculture and the environment.

The research shows that large numbers of kangaroos can reduce the occurrence of native grasses, which livestock graze on and can also affect the diversity and cover of shrubs and the quality of habitat for various native species including beetles, reptiles, birds and bandicoots.

However, wildlife health and conservation expert from the University of Sydney, Catherine Herbert said that more work would be needed to prove this.

"What we need to look at is the total grazing pressure within the system, [the] stocking rates of farmers and also understanding more about the extent to which kangaroos actually compete with livestock," she said.

What can farmers do about it?

A lack of demand for kangaroo meat means there is less work for shooters and the number of shooters is declining in some areas.